Spring boot + MongoDB 整合 增删改查及聚合写法

[code]import com.lhyt.mongodb.entity.UserEntity;
import com.mongodb.client.result.DeleteResult;
import com.mongodb.client.result.UpdateResult;
import org.bson.Document;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.aggregation.Aggregation;
import org.springframework.data.mongodb.core.aggregation.AggregationResults;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
* @author zhangYQi
*/

@RestController
@RequestMapping(value = "practice")
public class PracticeMongoDBController {

@Autowired
private MongoTemplate mongoTemplate;

/**
* 在user表中新增一条数据，
* ※ 注意字段名，返回值类型
*
* @return
*/
@RequestMapping(value = "getUser")
public UserEntity getUser() {
UserEntity userEntity = new UserEntity();
userEntity.setUserName("zyq+++");
userEntity.setPassword("zyq123+");
userEntity.setEmail("zyq111@qq");
userEntity.setAge(777);
userEntity.setName("zyq name ");
UserEntity userEntity7 = mongoTemplate.save(userEntity, "user");
return userEntity7;
}

/**
* 查询user表中的所有数据
*
* @return
*/
@RequestMapping(value = "queryAll")
public List<UserEntity> query() {
List<UserEntity> queryAll = mongoTemplate.findAll(UserEntity.class, "user");
return queryAll;
}

/**
* 根据条件查询
*/
@RequestMapping(value = "queryFind")
public List<UserEntity> queryFind() {
Query query = Query.query(Criteria.where("userName").is("zyq888"));
List<UserEntity> queryFinds = mongoTemplate.find(query, UserEntity.class, "user");
return queryFinds;
}

/**
* 根据条件查询，并删除查询结果
* ※ mongoTemplate点的是findAndRemove 不是 findAllRemove
*/
@RequestMapping(value = "findAndRemove")
public UserEntity findAndRemove() {
Query query = Query.query(Criteria.where("userName").is("zyq999"));
UserEntity userEntity = mongoTemplate.findAndRemove(query, UserEntity.class, "user");
return userEntity;
}

/**
* 删除查询出来的这一行，返回删除成功数值1
* 返回值类型：DeleteResult
*/
@RequestMapping(value = "delete")
public DeleteResult deleteUser() {
Query query = Query.query(Criteria.where("userName").is("zyq00"));
DeleteResult userEntity = mongoTemplate.remove(query, UserEntity.class, "user");
return userEntity;
}

/**
* 根据条件查行，有查询结果更改userName为zyq7890，有结果没字段不做操作
*
* @return
*/
@RequestMapping(value = "modify")
public UserEntity modify() {
Query query = Query.query(Criteria.where("userName").is("zyq770"));
Update update = new Update();
update.set("userName", "zyq7890");
UserEntity userEntity = mongoTemplate.findAndModify(query, update, UserEntity.class, "user");
return userEntity;
}

/**
* 更改查询结果的第一条
*/
@RequestMapping(value = "findFirst")
public UpdateResult findFirst() {
Query query = Query.query(Criteria.where("userName").is("zyq888"));
Update update = new Update();
update.set("password", "zyq6789");
UpdateResult userEntity = mongoTemplate.updateFirst(query, update, UserEntity.class, "user");
return userEntity;
}

/**
*根据条件查询，将查询结果中的password都改为zyq77788999
*/
@RequestMapping(value = "findMulti")
public UpdateResult findMulti() {
Query query = Query.query(Criteria.where("userName").is("zyq888"));
Update update = new Update();
update.set("password", "zyq777888999");
UpdateResult userEntity = mongoTemplate.updateMulti(query, update, UserEntity.class, "user");
return userEntity;
}

/**
* 聚合，分组
* 条件和分组参数以逗号结尾，回显字段(最后一行没有逗号)
* sum 求和， avg 分组平均值
* @return
*/
@RequestMapping(value = "aggregation")
public List<Document>  aggregate(){
Aggregation aggregation = Aggregation.newAggregation(
Aggregation.match(Criteria.where("userName").is("zyq888")),    //条件
Aggregation.group("userName").count().as("sumCount").sum("age").as("sumAge"), //分组参数
Aggregation.project("userName", "sumCount", "sumAge") // 回显字段
);
AggregationResults<Document> userEntity = mongoTemplate.aggregate(aggregation, "user", Document.class);
List<Document> aggregeter = userEntity.getMappedResults();
return aggregeter;
}

}

  聚合除求和以外，其他几种需求的写法（将上放sum更换成avg即可）：